bigbuffet-rw/app/soapbox/utils/theme.js
2020-10-01 18:57:11 -05:00

83 lines
2.2 KiB
JavaScript

import { Map as ImmutableMap } from 'immutable';
export const generateThemeCss = brandColor => {
if (!brandColor) return null;
return themeDataToCss(brandColorToThemeData(brandColor));
};
// https://stackoverflow.com/a/5624139
function hexToRgb(hex) {
// Expand shorthand form (e.g. "03F") to full form (e.g. "0033FF")
const shorthandRegex = /^#?([a-f\d])([a-f\d])([a-f\d])$/i;
hex = hex.replace(shorthandRegex, (m, r, g, b) => (
r + r + g + g + b + b
));
const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
return result ? {
r: parseInt(result[1], 16),
g: parseInt(result[2], 16),
b: parseInt(result[3], 16),
} : {
// fall back to Azure
r: 4,
g: 130,
b: 216,
};
}
// Taken from chromatism.js
// https://github.com/graypegg/chromatism/blob/master/src/conversions/rgb.js
const rgbToHsl = value => {
var r = value.r / 255;
var g = value.g / 255;
var b = value.b / 255;
var rgbOrdered = [ r, g, b ].sort();
var l = ((rgbOrdered[0] + rgbOrdered[2]) / 2) * 100;
var s, h;
if (rgbOrdered[0] === rgbOrdered[2]) {
s = 0;
h = 0;
} else {
if (l >= 50) {
s = ((rgbOrdered[2] - rgbOrdered[0]) / ((2.0 - rgbOrdered[2]) - rgbOrdered[0])) * 100;
} else {
s = ((rgbOrdered[2] - rgbOrdered[0]) / (rgbOrdered[2] + rgbOrdered[0])) * 100;
}
if (rgbOrdered[2] === r) {
h = ((g - b) / (rgbOrdered[2] - rgbOrdered[0])) * 60;
} else if (rgbOrdered[2] === g) {
h = (2 + ((b - r) / (rgbOrdered[2] - rgbOrdered[0]))) * 60;
} else {
h = (4 + ((r - g) / (rgbOrdered[2] - rgbOrdered[0]))) * 60;
}
if (h < 0) {
h += 360;
} else if (h > 360) {
h = h % 360;
}
}
return {
h: h,
s: s,
l: l,
};
};
export const brandColorToThemeData = brandColor => {
const { h, s, l } = rgbToHsl(hexToRgb(brandColor));
return ImmutableMap({
'brand-color_h': h,
'brand-color_s': `${s}%`,
'brand-color_l': `${l}%`,
});
};
export const themeDataToCss = themeData => (
themeData
.entrySeq()
.reduce((acc, cur) => acc + `--${cur[0]}:${cur[1]};`, '')
);
export const brandColorToCSS = brandColor => themeDataToCss(brandColorToThemeData(brandColor));